How many square feet in 10 gallon fish tank?

if its rectangular, often 20" x 10" x 12"

if its a 10gal long, often 24" x 8" x 12"

if its a 10gal high, often 16" x 8" x 17"

if its a hexagon, often 14" x 12" x 18"

measurements are length x width x height in inches

exact measurements may vary slightly depending on the manufacturer due to glass thickness and whether they measure the inside of the tank or the outside of the tank.